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Mahanta PJ, Lhouvum K. Plasmodium falciparum proteases as new drug targets with special focus on metalloproteases. Mol Biochem Parasitol 2024; 258:111617. [PMID: 38554736 DOI: 10.1016/j.molbiopara.2024.111617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 02/15/2024] [Accepted: 03/10/2024] [Indexed: 04/02/2024]
Abstract
Malaria poses a significant global health threat particularly due to the prevalence of Plasmodium falciparum infection. With the emergence of parasite resistance to existing drugs including the recently discovered artemisinin, ongoing research seeks novel therapeutic avenues within the malaria parasite. Proteases are promising drug targets due to their essential roles in parasite biology, including hemoglobin digestion, merozoite invasion, and egress. While exploring the genomic landscape of Plasmodium falciparum, it has been revealed that there are 92 predicted proteases, with only approximately 14 of them having been characterized. These proteases are further distributed among 26 families grouped into five clans: aspartic proteases, cysteine proteases, metalloproteases, serine proteases, and threonine proteases. Focus on metalloprotease class shows further role in organelle processing for mitochondria and apicoplasts suggesting the potential of metalloproteases as viable drug targets. Holistic understanding of the parasite intricate life cycle and identification of potential drug targets are essential for developing effective therapeutic strategies against malaria and mitigating its devastating global impact.
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Affiliation(s)
| | - Kimjolly Lhouvum
- Department of Biotechnology, National Institute of Technology, Arunachal Pradesh, India.
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2
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Kayiba NK, Tshibangu-Kabamba E, Rosas-Aguirre A, Kaku N, Nakagama Y, Kaneko A, Makaba DM, Malekita DY, Devleesschauwer B, Likwela JL, Zakayi PK, DeMol P, Lelo GM, Hayette MP, Dikassa PL, Kido Y, Speybroeck N. The landscape of drug resistance in Plasmodium falciparum malaria in the Democratic Republic of Congo: a mapping systematic review. Trop Med Health 2023; 51:64. [PMID: 37968745 PMCID: PMC10647042 DOI: 10.1186/s41182-023-00551-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 10/16/2023] [Indexed: 11/17/2023] Open
Abstract
CONTEXT The Democratic Republic of Congo (DRC), one of the most malaria-affected countries worldwide, is a potential hub for global drug-resistant malaria. This study aimed at summarizing and mapping surveys of malaria parasites carrying molecular markers of drug-resistance across the country. METHODS A systematic mapping review was carried out before July 2023 by searching for relevant articles through seven databases (PubMed, Embase, Scopus, African Journal Online, African Index Medicus, Bioline and Web of Science). RESULTS We identified 1541 primary studies of which 29 fulfilled inclusion criteria and provided information related to 6385 Plasmodium falciparum clinical isolates (collected from 2000 to 2020). We noted the PfCRT K76T mutation encoding for chloroquine-resistance in median 32.1% [interquartile interval, IQR: 45.2] of analyzed malaria parasites. The proportion of parasites carrying this mutation decreased overtime, but wide geographic variations persisted. A single isolate had encoded the PfK13 R561H substitution that is invoked in artemisinin-resistance emergence in the Great Lakes region of Africa. Parasites carrying various mutations linked to resistance to the sulfadoxine-pyrimethamine combination were widespread and reflected a moderate resistance profile (PfDHPS A437G: 99.5% [IQR: 3.9]; PfDHPS K540E: 38.9% [IQR: 47.7]) with median 13.1% [IQR: 10.3] of them being quintuple IRN-GE mutants (i.e., parasites carrying the PfDHFR N51I-C59R-S108N and PfDHPS A437G-K540E mutations). These quintuple mutants tended to prevail in eastern regions of the country. Among circulating parasites, we did not record any parasites harboring mutations related to mefloquine-resistance, but we could suspect those with decreased susceptibility to quinine, amodiaquine, and lumefantrine based on corresponding molecular surrogates. CONCLUSIONS Drug resistance poses a serious threat to existing malaria therapies and chemoprevention options in the DRC. This review provides a baseline for monitoring public health efforts as well as evidence for decision-making in support of national malaria policies and for implementing regionally tailored control measures across the country.
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Affiliation(s)
- Nadine Kalenda Kayiba
- Research Institute of Health and Society, Université Catholique de Louvain, Brussels, Belgium
- Department of Public Health, Faculty of Medicine, University of Mbujimayi, Mbujimayi, Democratic Republic of Congo
- Research Center for Infectious Disease Science & Department of Virology and Parasitology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
| | - Evariste Tshibangu-Kabamba
- Research Center for Infectious Disease Science & Department of Virology and Parasitology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
- Department of Internal Medicine, Faculty of Medicine, University of Mbujimayi, Mbujimayi, Democratic Republic of Congo
| | - Angel Rosas-Aguirre
- Research Institute of Health and Society, Université Catholique de Louvain, Brussels, Belgium
| | - Natsuko Kaku
- Research Center for Infectious Disease Science & Department of Virology and Parasitology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
| | - Yu Nakagama
- Research Center for Infectious Disease Science & Department of Virology and Parasitology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
| | - Akira Kaneko
- Research Center for Infectious Disease Science & Department of Virology and Parasitology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
| | - Dieudonné Mvumbi Makaba
- Department of Basic Sciences, Faculty of Medicine, University of Kinshasa, Kinshasa, Democratic Republic of Congo
- Department of Quality of Laboratories, Sciensano, Brussels, Belgium
| | - Doudou Yobi Malekita
- Department of Basic Sciences, Faculty of Medicine, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Brecht Devleesschauwer
- Department of Epidemiology and Public Health, Sciensano, Brussels, Belgium
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
| | - Joris Losimba Likwela
- Department of Public Health, Faculty of Medicine, University of Kisangani, Kisangani, Democratic Republic of Congo
| | - Pius Kabututu Zakayi
- Department of Basic Sciences, Faculty of Medicine, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Patrick DeMol
- Laboratory of Clinical Microbiology, Center for Interdisciplinary Research on Medicines, University of Liège, Liège, Belgium
| | - Georges Mvumbi Lelo
- Department of Basic Sciences, Faculty of Medicine, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Marie-Pierre Hayette
- Laboratory of Clinical Microbiology, Center for Interdisciplinary Research on Medicines, University of Liège, Liège, Belgium
| | - Paul Lusamba Dikassa
- School of Public Health, Faculty of Medicine, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Yasutoshi Kido
- Research Center for Infectious Disease Science & Department of Virology and Parasitology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan.
| | - Niko Speybroeck
- Research Institute of Health and Society, Université Catholique de Louvain, Brussels, Belgium
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3
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Kincaid JRA, Kavthe RD, Caravez JC, Takale BS, Thakore RR, Lipshutz BH. Environmentally Responsible and Cost-Effective Synthesis of the Antimalarial Drug Pyronaridine. Org Lett 2022; 24:3342-3346. [PMID: 35504038 PMCID: PMC9112334 DOI: 10.1021/acs.orglett.2c00944] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
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Two routes to the
antimalarial drug Pyronaridine are described.
The first is a linear sequence that includes a two-step, one-pot transformation
in an aqueous surfactant medium, leading to an overall yield of 87%.
Alternatively, a convergent route utilizes a telescoped three-step
sequence involving an initial neat reaction, followed by two steps
performed under aqueous micellar catalysis conditions affording Pyronaridine
in 95% overall yield. Comparisons to existing literature performed
exclusively in organic solvents reveal a 5-fold decrease in environmental
impact as measured by E Factors.
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Affiliation(s)
- Joseph R A Kincaid
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, California 93106 United States
| | - Rahul D Kavthe
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, California 93106 United States
| | - Juan C Caravez
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, California 93106 United States
| | - Balaram S Takale
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, California 93106 United States
| | - Ruchita R Thakore
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, California 93106 United States
| | - Bruce H Lipshutz
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, California 93106 United States
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Gil JP, Fançony C. Plasmodium falciparum Multidrug Resistance Proteins ( pfMRPs). Front Pharmacol 2021; 12:759422. [PMID: 34790129 PMCID: PMC8591188 DOI: 10.3389/fphar.2021.759422] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 10/05/2021] [Indexed: 12/19/2022] Open
Abstract
The capacity of the lethal Plasmodium falciparum parasite to develop resistance against anti-malarial drugs represents a central challenge in the global control and elimination of malaria. Historically, the action of drug transporters is known to play a pivotal role in the capacity of the parasite to evade drug action. MRPs (Multidrug Resistance Protein) are known in many phylogenetically diverse groups to be related to drug resistance by being able to handle a large range of substrates, including important endogenous substances as glutathione and its conjugates. P. falciparum MRPs are associated with in vivo and in vitro altered drug response, and might be important factors for the development of multi-drug resistance phenotypes, a latent possibility in the present, and future, combination therapy environment. Information on P. falciparum MRPs is scattered in the literature, with no specialized review available. We herein address this issue by reviewing the present state of knowledge.
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Affiliation(s)
- José Pedro Gil
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.,Faculty of Sciences, BioISI-Biosystems and Integrative Sciences Institute, University of Lisbon, Lisbon, Portugal.,Global Health and Tropical Medicine, Institute of Hygiene and Tropical Medicine, Nova University of Lisbon, Lisbon, Portugal
| | - Cláudia Fançony
- Centro de Investigação em Saúde de Angola (CISA)/Instituto Nacional de Investigação em Saúde (INIS), Caxito, Angola
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Mahotorn K, Tan-Ariya P, Thita T, Ruang-Areerate T, Sittichot N, Suwandittakul N, Mungthin M. In Vitro Sensitivity of Pyronaridine in Thai Isolates of Plasmodium falciparum. Am J Trop Med Hyg 2018; 98:51-56. [PMID: 29141758 DOI: 10.4269/ajtmh.17-0286] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Pyronaridine, a Mannich base antimalarial agent with a high activity against chloroquine-resistant Plasmodium falciparum, has been combined with artesunate as a new artemisinin based combination therapy (ACT). Pyronaridine-artesunate combination could be one of the choices for the treatment of uncomplicated falciparum malaria in multidrug-resistant areas including Thailand. The aim of this study was to determine in vitro sensitivity and cross-resistance pattern of pyronaridine in Thai isolates of P. falciparum. In addition, the influence of resistant genes concerning in vitro pyronaridine sensitivity was determined. The mean pyronaridine 50% inhibitory concentration (IC50) of 118 parasite isolates was 5.6 ± 3.1 nM (range = 0.2-15.4 nM) with a significant positive correlation with artesunate IC50 (r = 0.246, P = 0.008) and amodiaquine IC50 (r = 0.220, P = 0.042) and a significant negative correlation with quinine IC50 (r = -0.185, P = 0.047). Parasites containing the pfmdr1 86Y allele exhibited significantly reduced pyronaridine sensitivity compared with those with the pfmdr1 N86 allele (7.6 ± 3.3 nM and 5.4 ± 3.0 nM, respectively, P = 0.032, independent t test); however, the difference may not be clinically relevant. Pyronaridine-artesunate could be the candidate ACT to treat multidrug-resistant falciparum malaria in Thailand with careful monitoring.
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Affiliation(s)
- Kittiya Mahotorn
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - Peerapan Tan-Ariya
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - Thunyapit Thita
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - Toon Ruang-Areerate
- Department of Parasitology, Phramongkutklao College of Medicine, Bangkok 10400, Thailand
| | - Naruemon Sittichot
- Department of Parasitology, Phramongkutklao College of Medicine, Bangkok 10400, Thailand
| | - Nantana Suwandittakul
- Department of Parasitology, Phramongkutklao College of Medicine, Bangkok 10400, Thailand
| | - Mathirut Mungthin
- Department of Parasitology, Phramongkutklao College of Medicine, Bangkok 10400, Thailand
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The Redox Cycler Plasmodione Is a Fast-Acting Antimalarial Lead Compound with Pronounced Activity against Sexual and Early Asexual Blood-Stage Parasites. Antimicrob Agents Chemother 2016; 60:5146-58. [PMID: 27297478 DOI: 10.1128/aac.02975-15] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Accepted: 05/27/2016] [Indexed: 01/16/2023] Open
Abstract
Previously, we presented the chemical design of a promising series of antimalarial agents, 3-[substituted-benzyl]-menadiones, with potent in vitro and in vivo activities. Ongoing studies on the mode of action of antimalarial 3-[substituted-benzyl]-menadiones revealed that these agents disturb the redox balance of the parasitized erythrocyte by acting as redox cyclers-a strategy that is broadly recognized for the development of new antimalarial agents. Here we report a detailed parasitological characterization of the in vitro activity profile of the lead compound 3-[4-(trifluoromethyl)benzyl]-menadione 1c (henceforth called plasmodione) against intraerythrocytic stages of the human malaria parasite Plasmodium falciparum We show that plasmodione acts rapidly against asexual blood stages, thereby disrupting the clinically relevant intraerythrocytic life cycle of the parasite, and furthermore has potent activity against early gametocytes. The lead's antiplasmodial activity was unaffected by the most common mechanisms of resistance to clinically used antimalarials. Moreover, plasmodione has a low potential to induce drug resistance and a high killing speed, as observed by culturing parasites under continuous drug pressure. Drug interactions with licensed antimalarial drugs were also established using the fixed-ratio isobologram method. Initial toxicological profiling suggests that plasmodione is a safe agent for possible human use. Our studies identify plasmodione as a promising antimalarial lead compound and strongly support the future development of redox-active benzylmenadiones as antimalarial agents.
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Madamet M, Briolant S, Amalvict R, Benoit N, Bouchiba H, Cren J, Pradines B. The Plasmodium falciparum chloroquine resistance transporter is associated with the ex vivo P. falciparum African parasite response to pyronaridine. Parasit Vectors 2016; 9:77. [PMID: 26858119 PMCID: PMC4746765 DOI: 10.1186/s13071-016-1358-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 02/03/2016] [Indexed: 01/10/2023] Open
Abstract
Background The pyronaridine-artesunate combination is one of the most recent oral artemisinin-based therapeutic combinations (ACTs) recommended for the treatment of uncomplicated P. falciparum malaria. The emergence of P. falciparum resistance to artemisinin has recently developed in Southeast Asia. Little data are available on the association between pyronaridine susceptibility and polymorphisms in genes involved in antimalarial drug resistance. The objective of the present study was to investigate the association between ex vivo responses to pyronaridine and the K76T mutation in the pfcrt gene in P. falciparum isolates. Methods The assessment of ex vivo susceptibility to pyronaridine was performed on 296 P. falciparum isolates using a standard 42-h 3H-hypoxanthine uptake inhibition method. The K76T mutation was also investigated. Results The pyronaridine IC50 (inhibitory concentration 50 %) ranged from 0.55 to 80.0 nM. Ex vivo responses to pyronaridine were significantly associated with the K76T mutation (p-value = 0.020). The reduced susceptibility to pyronaridine, defined as IC50 > 60 nM, was significantly associated with the K76T mutation (p-value = 0.004). Using a Bayesian mixture modelling approach, the pyronaridine IC50 were classified into three components: component A (IC50 median 15.9 nM), component B (IC50 median 34.2 nM) and component C (IC50 median 63.3 nM). The K76T mutation was represented in 46.3 % of the isolates in component A, 47.2 % of the isolates in component B and 73.3 % of the isolates in component C (p-value = 0.021). Conclusion These results showed the ex vivo reduced susceptibility to pyronaridine, i.e., IC50 > 60 nM, associated with the K76T mutation.
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Affiliation(s)
- Marylin Madamet
- Equipe Résidente de Recherche en Infectiologie Tropicale, Institut de Recherche Biomédicale des Armées, Hôpital d'Instruction des Armées Laveran, Marseille, France. .,Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Aix Marseille Université, UM 63, CNRS 7278, IRD 198, Inserm 1095, Marseille, France. .,Centre National de Référence du Paludisme, Marseille, France.
| | - Sébastien Briolant
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Aix Marseille Université, UM 63, CNRS 7278, IRD 198, Inserm 1095, Marseille, France. .,Unité de Parasitologie et d'Entomologie, Département des Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, Brétigny sur Orge, France. .,Direction Interarmées du Service de Santé, Cayenne, Guyane, France. .,Laboratoire de Parasitologie, Institut Pasteur de la Guyane, Cayenne, Guyane, France.
| | - Rémy Amalvict
- Equipe Résidente de Recherche en Infectiologie Tropicale, Institut de Recherche Biomédicale des Armées, Hôpital d'Instruction des Armées Laveran, Marseille, France. .,Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Aix Marseille Université, UM 63, CNRS 7278, IRD 198, Inserm 1095, Marseille, France. .,Centre National de Référence du Paludisme, Marseille, France.
| | - Nicolas Benoit
- Equipe Résidente de Recherche en Infectiologie Tropicale, Institut de Recherche Biomédicale des Armées, Hôpital d'Instruction des Armées Laveran, Marseille, France. .,Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Aix Marseille Université, UM 63, CNRS 7278, IRD 198, Inserm 1095, Marseille, France. .,Centre National de Référence du Paludisme, Marseille, France.
| | - Housem Bouchiba
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Aix Marseille Université, UM 63, CNRS 7278, IRD 198, Inserm 1095, Marseille, France. .,Unité de Parasitologie et d'Entomologie, Département des Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, Brétigny sur Orge, France.
| | - Julien Cren
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Aix Marseille Université, UM 63, CNRS 7278, IRD 198, Inserm 1095, Marseille, France.,Unité de Parasitologie et d'Entomologie, Département des Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, Brétigny sur Orge, France
| | - Bruno Pradines
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Aix Marseille Université, UM 63, CNRS 7278, IRD 198, Inserm 1095, Marseille, France. .,Centre National de Référence du Paludisme, Marseille, France. .,Unité de Parasitologie et d'Entomologie, Département des Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, Brétigny sur Orge, France.
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Ex Vivo Drug Susceptibility Testing and Molecular Profiling of Clinical Plasmodium falciparum Isolates from Cambodia from 2008 to 2013 Suggest Emerging Piperaquine Resistance. Antimicrob Agents Chemother 2015; 59:4631-43. [PMID: 26014942 DOI: 10.1128/aac.00366-15] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 05/18/2015] [Indexed: 12/26/2022] Open
Abstract
Cambodia's first-line artemisinin combination therapy, dihydroartemisinin-piperaquine (DHA-PPQ), is no longer sufficiently curative against multidrug-resistant Plasmodium falciparum malaria at some Thai-Cambodian border regions. We report recent (2008 to 2013) drug resistance trends in 753 isolates from northern, western, and southern Cambodia by surveying for ex vivo drug susceptibility and molecular drug resistance markers to guide the selection of an effective alternative to DHA-PPQ. Over the last 3 study years, PPQ susceptibility declined dramatically (geomean 50% inhibitory concentration [IC50] increased from 12.8 to 29.6 nM), while mefloquine (MQ) sensitivity doubled (67.1 to 26 nM) in northern Cambodia. These changes in drug susceptibility were significantly associated with a decreased prevalence of P. falciparum multidrug resistance 1 gene (Pfmdr1) multiple copy isolates and coincided with the timing of replacing artesunate-mefloquine (AS-MQ) with DHA-PPQ as the first-line therapy. Widespread chloroquine resistance was suggested by all isolates being of the P. falciparum chloroquine resistance transporter gene CVIET haplotype. Nearly all isolates collected from the most recent years had P. falciparum kelch13 mutations, indicative of artemisinin resistance. Ex vivo bioassay measurements of antimalarial activity in plasma indicated 20% of patients recently took antimalarials, and their plasma had activity (median of 49.8 nM DHA equivalents) suggestive of substantial in vivo drug pressure. Overall, our findings suggest DHA-PPQ failures are associated with emerging PPQ resistance in a background of artemisinin resistance. The observed connection between drug policy changes and significant reduction in PPQ susceptibility with mitigation of MQ resistance supports reintroduction of AS-MQ, in conjunction with monitoring of the P. falciparum mdr1 copy number, as a stop-gap measure in areas of DHA-PPQ failure.
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Pascual A, Madamet M, Briolant S, Gaillard T, Amalvict R, Benoit N, Travers D, Pradines B. Multinormal in vitro distribution of Plasmodium falciparum susceptibility to piperaquine and pyronaridine. Malar J 2015; 14:49. [PMID: 25848972 PMCID: PMC4323025 DOI: 10.1186/s12936-015-0586-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 01/26/2015] [Indexed: 12/27/2022] Open
Abstract
Background In 2002, the World Health Organization recommended that artemisinin-based combination therapy (ACT) be used to treat uncomplicated malaria. Dihydroartemisinin-piperaquine and artesunate-pyronaridine are two of these new combinations. The aim of the present work was to assess the distribution of the in vitro values of pyronaridine (PND) and piperaquine (PPQ) and to define a cut-off for reduced susceptibility for the two anti-malarial drugs. Methods The distribution and range of the 50% inhibitory concentration values (IC50) of PND and PPQ were determined for 313 isolates obtained between 2008 and 2012 from patients hospitalized in France for imported malaria. The statistical Bayesian analysis was designed to answer the specific question of whether Plasmodium falciparum has different phenotypes of susceptibility to PND and PPQ. Results The PND IC50 values ranged from 0.6 to 84.6 nM, with a geometric mean of 21.1 ± 16.0 nM (standard deviation). These values were classified into three components. The PPQ IC50 values ranged from 9.8 to 217.3 nM, and the geometric mean was 58.0 ± 34.5 nM. All 313 PPQ values were classified into four components. Isolates with IC50 values greater than 60 nM or four-fold greater than 3D7 IC50 are considered isolates that have reduced susceptibility to PND and those with IC50 values greater than 135 nM or 2.3-fold greater than 3D7 IC50 are considered isolates that have reduced susceptibility to PPQ. Conclusion The existence of at least three phenotypes for PND and four phenotypes for PPQ was demonstrated. Based on the cut-off values, 18 isolates (5.8%) and 13 isolates (4.2%) demonstrated reduced susceptibility to PND and PPQ, respectively.
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Koleala T, Karl S, Laman M, Moore BR, Benjamin J, Barnadas C, Robinson LJ, Kattenberg JH, Javati S, Wong RPM, Rosanas-Urgell A, Betuela I, Siba PM, Mueller I, Davis TME. Temporal changes in Plasmodium falciparum anti-malarial drug sensitivity in vitro and resistance-associated genetic mutations in isolates from Papua New Guinea. Malar J 2015; 14:37. [PMID: 25626445 PMCID: PMC4335551 DOI: 10.1186/s12936-015-0560-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 01/13/2015] [Indexed: 01/19/2023] Open
Abstract
Background In northern Papua New Guinea (PNG), most Plasmodium falciparum isolates proved resistant to chloroquine (CQ) in vitro between 2005 and 2007, and there was near-fixation of pfcrt K76T, pfdhfr C59R/S108N and pfmdr1 N86Y. To determine whether the subsequent introduction of artemisinin combination therapy (ACT) and reduced CQ-sulphadoxine-pyrimethamine pressure had attenuated parasite drug susceptibility and resistance-associated mutations, these parameters were re-assessed between 2011 and 2013. Methods A validated fluorescence-based assay was used to assess growth inhibition of 52 P. falciparum isolates from children in a clinical trial in Madang Province. Responses to CQ, lumefantrine, piperaquine, naphthoquine, pyronaridine, artesunate, dihydroartemisinin, artemether were assessed. Molecular resistance markers were detected using a multiplex PCR ligase detection reaction fluorescent microsphere assay. Results CQ resistance (in vitro concentration required for 50% parasite growth inhibition (IC50) >100 nM) was present in 19% of isolates. All piperaquine and naphthoquine IC50s were <100 nM and those for lumefantrine, pyronaridine and the artemisinin derivatives were in low nM ranges. Factor analysis of IC50s showed three groupings (lumefantrine; CQ, piperaquine, naphthoquine; pyronaridine, dihydroartemisinin, artemether, artesunate). Most isolates (96%) were monoclonal pfcrt K76T (SVMNT) mutants and most (86%) contained pfmdr1 N86Y (YYSND). No wild-type pfdhfr was found but most isolates contained wild-type (SAKAA) pfdhps. Compared with 2005–2007, the geometric mean (95% CI) CQ IC50 was lower (87 (71–107) vs 167 (141–197) nM) and there had been no change in the prevalence of pfcrt K76T or pfmdr1 mutations. There were fewer isolates of the pfdhps (SAKAA) wild-type (60 vs 100%) and pfdhfr mutations persisted. Conclusions Reflecting less drug pressure, in vitro CQ sensitivity appears to be improving in Madang Province despite continued near-fixation of pfcrt K76T and pfmdr1 mutations. Temporal changes in IC50s for other anti-malarial drugs were inconsistent but susceptibility was preserved. Retention or increases in pfdhfr and pfdhps mutations reflect continued use of sulphadoxine-pyrimethamine in the study area including through paediatric intermittent preventive treatment. The susceptibility of local isolates to lumefantrine may be unrelated to those of other ACT partner drugs. Trial registration Australian New Zealand Clinical Trials Registry ACTRN12610000913077.
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Affiliation(s)
- Tamarah Koleala
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.
| | - Stephan Karl
- School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, PO Box 480, Fremantle, 6959, WA, Australia. .,Infection and Immunity Division, Walter and Eliza Hall Institute, Parkville, VIC, Australia. .,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia.
| | - Moses Laman
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea. .,School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, PO Box 480, Fremantle, 6959, WA, Australia.
| | - Brioni R Moore
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea. .,School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, PO Box 480, Fremantle, 6959, WA, Australia.
| | - John Benjamin
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.
| | - Celine Barnadas
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea. .,Infection and Immunity Division, Walter and Eliza Hall Institute, Parkville, VIC, Australia. .,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia.
| | - Leanne J Robinson
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea. .,Infection and Immunity Division, Walter and Eliza Hall Institute, Parkville, VIC, Australia. .,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia.
| | - Johanna H Kattenberg
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea. .,Infection and Immunity Division, Walter and Eliza Hall Institute, Parkville, VIC, Australia.
| | - Sarah Javati
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.
| | - Rina P M Wong
- School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, PO Box 480, Fremantle, 6959, WA, Australia.
| | - Anna Rosanas-Urgell
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea. .,Institute of Tropical Medicine, Antwerp, Belgium.
| | - Inoni Betuela
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.
| | - Peter M Siba
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.
| | - Ivo Mueller
- Infection and Immunity Division, Walter and Eliza Hall Institute, Parkville, VIC, Australia. .,Center de Recerca en Salut Internacional de Barcelona (CRESIB), Barcelona, Spain.
| | - Timothy M E Davis
- School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, PO Box 480, Fremantle, 6959, WA, Australia.
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11
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Bukirwa H, Unnikrishnan B, Kramer CV, Sinclair D, Nair S, Tharyan P. Artesunate plus pyronaridine for treating uncomplicated Plasmodium falciparum malaria. Cochrane Database Syst Rev 2014:CD006404. [PMID: 24596021 PMCID: PMC4448218 DOI: 10.1002/14651858.cd006404.pub2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND The World Health Organization (WHO) recommends that people with uncomplicated Plasmodium falciparum malaria are treated using Artemisinin-based Combination Therapy (ACT). ACT combines three-days of a short-acting artemisinin derivative with a longer-acting antimalarial which has a different mode of action. Pyronaridine has been reported as an effective antimalarial over two decades of use in parts of Asia, and is currently being evaluated as a partner drug for artesunate. OBJECTIVES To evaluate the efficacy and safety of artesunate-pyronaridine compared to alternative ACTs for treating people with uncomplicated P. falciparum malaria. SEARCH METHODS We searched the Cochrane Infectious Diseases Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL), published in The Cochrane Library; MEDLINE; EMBASE; LILACS; ClinicalTrials.gov; the metaRegister of Controlled Trials (mRCT); and the WHO International Clinical Trials Search Portal up to 16 January 2014. We searched reference lists and conference abstracts, and contacted experts for information about ongoing and unpublished trials. SELECTION CRITERIA Randomized controlled trials of artesunate-pyronaridine versus other ACTs in adults and children with uncomplicated P. falciparum malaria.For the safety analysis, we also included adverse events data from trials comparing any treatment regimen containing pyronaridine with regimens not containing pyronaridine. DATA COLLECTION AND ANALYSIS Two authors independently assessed trial eligibility and risk of bias, and extracted data. We combined dichotomous data using risk ratios (RR) and continuous data using mean differences (MD), and presented all results with a 95% confidence interval (CI). We used the GRADE approach to assess the quality of evidence. MAIN RESULTS We included six randomized controlled trials enrolling 3718 children and adults. Artesunate-pyronaridine versus artemether-lumefantrineIn two multicentre trials, enrolling mainly older children and adults from west and south-central Africa, both artesunate-pyronaridine and artemether-lumefantrine had fewer than 5% PCR adjusted treatment failures during 42 days of follow-up, with no differences between groups (two trials, 1472 participants, low quality evidence). There were fewer new infections during the first 28 days in those given artesunate-pyronaridine (PCR-unadjusted treatment failure: RR 0.60, 95% CI 0.40 to 0.90, two trials, 1720 participants, moderate quality evidence), but no difference was detected over the whole 42 day follow-up (two trials, 1691 participants, moderate quality evidence). Artesunate-pyronaridine versus artesunate plus mefloquineIn one multicentre trial, enrolling mainly older children and adults from South East Asia, both artesunate-pyronaridine and artesunate plus mefloquine had fewer than 5% PCR adjusted treatment failures during 28 days follow-up (one trial, 1187 participants, moderate quality evidence). PCR-adjusted treatment failures were 6% by day 42 for these treated with artesunate-pyronaridine, and 4% for those with artesunate-mefloquine (RR 1.64, 95% CI 0.89 to 3.00, one trial, 1116 participants, low quality evidence). Again, there were fewer new infections during the first 28 days in those given artesunate-pyronaridine (PCR-unadjusted treatment failure: RR 0.35, 95% CI 0.17 to 0.73, one trial, 1720 participants, moderate quality evidence), but no differences were detected over the whole 42 days (one trial, 1146 participants, low quality evidence). Adverse effectsSerious adverse events were uncommon in these trials, with no difference detected between artesunate-pyronaridine and comparator ACTs. The analysis of liver function tests showed biochemical elevation were four times more frequent with artesunate-pyronaridine than with the other antimalarials (RR 4.17, 95% CI 1.38 to 12.62, four trials, 3523 participants, moderate quality evidence). AUTHORS' CONCLUSIONS Artesunate-pyronaridine performed well in these trials compared to artemether-lumefantrine and artesunate plus mefloquine, with PCR-adjusted treatment failure at day 28 below the 5% standard set by the WHO. Further efficacy and safety studies in African and Asian children are required to clarify whether this combination is an option for first-line treatment.
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Affiliation(s)
| | - B Unnikrishnan
- Department of Community Medicine, Kasturba Medical CollegeMangalore, India
| | - Christine V Kramer
- Cochrane Infectious Diseases Group, Liverpool School of Tropical MedicineLiverpool, UK
| | - David Sinclair
- Department of Clinical Sciences, Liverpool School of Tropical MedicineLiverpool, UK
| | - Suma Nair
- Community Medicine, Kasturba Medical CollegeManipal, India
| | - Prathap Tharyan
- South Asian Cochrane Network & Centre, Prof. BV Moses Centre for Evidence-Informed Health Care and Health Policy, Christian Medical CollegeVellore, India
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12
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Kurth F, Bélard S, Basra A, Ramharter M. Pyronaridine: a new ‘old’ drug on the verge of entering the antimalarial armamentarium. Expert Rev Anti Infect Ther 2014; 9:393-6. [DOI: 10.1586/eri.11.17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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13
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Evidence for pyronaridine as a highly effective partner drug for treatment of artemisinin-resistant malaria in a rodent model. Antimicrob Agents Chemother 2013; 58:183-95. [PMID: 24145526 DOI: 10.1128/aac.01466-13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The increasing prevalence in Southeast Asia of Plasmodium falciparum infections with delayed parasite clearance rates, following treatment of malaria patients with the artemisinin derivative artesunate, highlights an urgent need to identify which of the currently available artemisinin-based combination therapies (ACTs) are most suitable to treat populations with emerging artemisinin resistance. Here, we demonstrate that the rodent Plasmodium berghei SANA strain has acquired artemisinin resistance following drug pressure, as defined by reduced parasite clearance and early recrudescence following daily exposure to high doses of artesunate or the active metabolite dihydroartemisinin. Using the SANA strain and the parental drug-sensitive N strain, we have interrogated the antimalarial activity of five ACTs, namely, artemether-lumefantrine, artesunate-amodiaquine, artesunate-mefloquine, dihydroartemisinin-piperaquine, and the newest combination artesunate-pyronaridine. By monitoring parasitemia and outcome for 30 days following initiation of treatment, we found that infections with artemisinin-resistant P. berghei SANA parasites can be successfully treated with artesunate-pyronaridine used at doses that are curative for the parental drug-sensitive N strain. No other partner drug combination was as effective in resolving SANA infections. Of the five partner drugs tested, pyronaridine was also the most effective at suppressing the recrudescence of SANA parasites. These data support the potential benefit of implementing ACTs with pyronaridine in regions affected by artemisinin-resistant malaria.
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14
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van Schalkwyk DA, Burrow R, Henriques G, Gadalla NB, Beshir KB, Hasford C, Wright SG, Ding XC, Chiodini PL, Sutherland CJ. Culture-adapted Plasmodium falciparum isolates from UK travellers: in vitro drug sensitivity, clonality and drug resistance markers. Malar J 2013; 12:320. [PMID: 24028570 PMCID: PMC3847303 DOI: 10.1186/1475-2875-12-320] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 09/10/2013] [Indexed: 01/20/2023] Open
Abstract
Background The screening of lead compounds against in vitro parasite cultures is an essential step in the development of novel anti-malarial drugs, but currently relies on laboratory parasite lines established in vitro during the last century. This study sought to establish in continuous culture a series of recent Plasmodium falciparum isolates to represent the current parasite populations in Africa, all of which are now exposed to artemisinin combination therapy. Methods Pre-treatment P. falciparum isolates were obtained in EDTA, and placed into continuous culture after sampling of DNA. One post-treatment blood sample was also collected for each donor to monitor parasite clonality during clearance in vivo. IC50 estimates were obtained for 11 anti-malarial compounds for each established parasite line, clonal multiplicity measured in vivo and in vitro, and polymorphic sites implicated in parasite sensitivity to drugs were investigated at the pfmdr1, pfcrt, pfdhfr, pfdhps and pfap2mu loci before and after treatment, and in the cultured lines. Results Plasmodium falciparum isolates from seven malaria patients with recent travel to three West African and two East African countries were successfully established in long-term culture. One of these, HL1211, was from a patient with recrudescent parasitaemia 14 days after a full course of artemether-lumefantrine. All established culture lines were shown to be polyclonal, reflecting the in vivo isolates from which they were derived, and at least two lines reliably produce gametocytes in vitro. Two lines displayed high chloroquine IC50 estimates, and carried the CVIET haplotype at codons 72–76, whereas the remaining five lines carried the CVMNK haplotype and were sensitive in vitro. All were sensitive to the endoperoxides dihydroartemisinin and OZ277, but IC50 estimates for lumefantrine varied, with the least sensitive parasites carrying pfmdr1 alleles encoding Asn at codon 86. Conclusions This study describes the establishment in continuous culture, in vitro drug sensitivity testing and molecular characterization of a series of multiclonal P. falciparum isolates taken directly from UK malaria patients following recent travel to various malaria-endemic countries in Africa. These “HL” isolates are available as an open resource for studies of drug response, antigenic diversity and other aspects of parasite biology.
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Affiliation(s)
- Donelly A van Schalkwyk
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
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15
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Summers RL, Nash MN, Martin RE. Know your enemy: understanding the role of PfCRT in drug resistance could lead to new antimalarial tactics. Cell Mol Life Sci 2012; 69:1967-95. [PMID: 22286067 PMCID: PMC11115045 DOI: 10.1007/s00018-011-0906-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Revised: 11/22/2011] [Accepted: 12/06/2011] [Indexed: 10/14/2022]
Abstract
The prevention and treatment of malaria is heavily dependent on antimalarial drugs. However, beginning with the emergence of chloroquine (CQ)-resistant Plasmodium falciparum parasites 50 years ago, efforts to control the disease have been thwarted by failed or failing drugs. Mutations in the parasite's 'chloroquine resistance transporter' (PfCRT) are the primary cause of CQ resistance. Furthermore, changes in PfCRT (and in several other transport proteins) are associated with decreases or increases in the parasite's susceptibility to a number of other antimalarial drugs. Here, we review recent advances in our understanding of CQ resistance and discuss these in the broader context of the parasite's susceptibilities to other quinolines and related drugs. We suggest that PfCRT can be viewed both as a 'multidrug-resistance carrier' and as a drug target, and that the quinoline-resistance mechanism is a potential 'Achilles' heel' of the parasite. We examine a number of the antimalarial strategies currently undergoing development that are designed to exploit the resistance mechanism, including relatively simple measures, such as alternative CQ dosages, as well as new drugs that either circumvent the resistance mechanism or target it directly.
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Affiliation(s)
- Robert L. Summers
- Research School of Biology, The Australian National University, Canberra, ACT 0200 Australia
| | - Megan N. Nash
- Research School of Biology, The Australian National University, Canberra, ACT 0200 Australia
| | - Rowena E. Martin
- Research School of Biology, The Australian National University, Canberra, ACT 0200 Australia
- School of Botany, University of Melbourne, Parkville, VIC 3010 Australia
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16
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Pascual A, Parola P, Benoit-Vical F, Simon F, Malvy D, Picot S, Delaunay P, Basset D, Maubon D, Faugère B, Ménard G, Bourgeois N, Oeuvray C, Didillon E, Rogier C, Pradines B. Ex vivo activity of the ACT new components pyronaridine and piperaquine in comparison with conventional ACT drugs against isolates of Plasmodium falciparum. Malar J 2012; 11:45. [PMID: 22333675 PMCID: PMC3305508 DOI: 10.1186/1475-2875-11-45] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Accepted: 02/14/2012] [Indexed: 01/29/2023] Open
Abstract
Background The aim of the present work was to assess i) ex vivo activity of pyronaridine (PND) and piperaquine (PPQ), as new components of artemisinin-based combination therapy (ACT), to define susceptibility baseline, ii) their activities compared to other partner drugs, namely monodesethylamodiaquine (MDAQ), lumefantrine (LMF), mefloquine (MQ), artesunate (AS) and dihydroartemisinin (DHA) against 181 Plasmodium falciparum isolates from African countries, India and Thailand, and iii) in vitro cross-resistance with other quinoline drugs, chloroquine (CQ) or quinine (QN). Methods The susceptibility of the 181 P. falciparum isolates to the nine anti-malarial drugs was assessed using the standard 42-hours 3H-hypoxanthine uptake inhibition method. Results The IC50 values for PND ranged from 0.55 to 80.0 nM (geometric mean = 19.9 nM) and from 11.8 to 217.3 nM for PPQ (geometric mean = 66.8 nM). A significant positive correlation was shown between responses to PPQ and PND responses (rho = 0.46) and between PPQ and MDAQ (rho = 0.30). No significant correlation was shown between PPQ IC50 and responses to other anti-malarial drugs. A significant positive correlation was shown between responses to PND and MDAQ (rho = 0.37), PND and LMF (rho = 0.28), PND and QN (rho = 0.24), PND and AS (rho = 0.19), PND and DHA (rho = 0.18) and PND and CQ (rho = 0.16). All these coefficients of correlation are too low to suggest cross-resistance between PPQ or PND and the other drugs. Conclusions In this study, the excellent anti-malarial activity of PPQ and PND was confirmed. The absence of cross-resistance with quinolines and artemisinin derivatives is consistent with the efficacy of the combinations of PPQ and DHA or PND and AS in areas where parasites are resistant to conventional anti-malarial drugs.
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Affiliation(s)
- Aurélie Pascual
- Unité de Recherche en Biologie et Epidémiologie Parasitaires Unité de Recherche pour les Maladies Infectieuses et Tropicales Emergentes UMR-6236, Institut de Recherche Biomédicale des Armées, Allée du Médecin-colonel Jamot,-BP 60109, 13262 Marseille Cedex, France
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Yu XM, Ramiandrasoa F, Guetzoyan L, Pradines B, Quintino E, Gadelle D, Forterre P, Cresteil T, Mahy JP, Pethe S. Synthesis and biological evaluation of acridine derivatives as antimalarial agents. ChemMedChem 2012; 7:587-605. [PMID: 22331612 DOI: 10.1002/cmdc.201100554] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 01/13/2012] [Indexed: 11/11/2022]
Abstract
New N-alkylaminoacridine derivatives attached to nitrogen heterocycles were synthesized, and their antimalarial potency was examined. They were tested in vitro against the growth of Plasmodium falciparum, including chloroquine (CQ)-susceptible and CQ-resistant strains. This biological evaluation has shown that the presence of a heterocyclic ring significantly increases the activity against P. falciparum. The best compound shows a nanomolar IC(50) value toward parasite proliferation on both CQ-susceptible and CQ-resistant strains. The antimalarial activity of these new acridine derivatives can be explained by the two mechanisms studied in this work. First, we showed the capacity of these compounds to inhibit heme biocrystallization, a detoxification process specific to the parasite and essential for its survival. Second, in our search for alternative targets, we evaluated the in vitro inhibitory activity of these compounds toward Sulfolobus shibatae topoisomerase VI-mediated DNA relaxation. The preliminary results obtained reveal that all tested compounds are potent DNA intercalators, and significantly inhibit the activity of S. shibatae topoisomerase VI at concentrations ranging between 2.0 and 2.5 μM.
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Affiliation(s)
- Xiao-Min Yu
- Université Paris-Sud 11, Institut de Chimie Moléculaire et des Matériaux d'Orsay, Equipe de Chimie Bioorganique et Bioinorganique, Orsay 91405 CEDEX, France
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Abstract
PURPOSE OF REVIEW Pyronaridine-artesunate is among the most promising novel artemisinin combination therapies for the treatment of malaria. A series of clinical phase II and III trials have been conducted for the indications of uncomplicated falciparum and vivax malaria in Africa and Asia. On the basis of these novel data, this review aims to provide an appraisal of current evidence and a perspective for its future role in the antimalarial portfolio. RECENT FINDINGS Pyronaridine-artesunate demonstrated repeatedly high efficacy in the treatment of vivax and falciparum malaria and noninferiority was established compared to standard comparator regimens. An innovative paediatric drug formulation was developed in parallel to the tablet formulation for the treatment of young children. Pharmacokinetic analysis showed dose linearity, low interindividual variation and absence of a clinically important effect of food on the bioavailability of this drug combination. Overall tolerability and safety data are reassuring; however, further surveillance of safety in special patient populations including young children is warranted. SUMMARY Pyronaridine-artesunate - currently under evaluation by the European Medicines Agency - may become a preferred choice as first-line therapy in malaria endemic regions based on its low cost, long shelf-life, simplified once-daily dosing regimen, proven efficacy against falciparum and vivax malaria, and the parallel clinical development of a paediatric drug formulation.
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Baseline in vitro activities of the antimalarials pyronaridine and methylene blue against Plasmodium falciparum isolates from Kenya. Antimicrob Agents Chemother 2011; 56:1105-7. [PMID: 22123687 DOI: 10.1128/aac.05454-11] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
We have analyzed the in vitro activities of pyronaridine and methylene blue against 59 Plasmodium falciparum isolates from Kenya in association with polymorphisms in Pfcrt (codon 76), Pfmdr1 (codon 86), and Pfnhe (full sequence). The median inhibitory concentrations that kill 50% of parasites were 13.5 and 3.3 nM for pyronaridine and methylene blue, respectively. Their activities were not associated with polymorphisms in these genes. The drugs' high in vitro activities indicate that they would be efficacious against Kenyan isolates in vivo.
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